<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8">
    <title>扫码登录</title>
</head>
<body>
<h2>实时显示</h2>
<div th:switch="${res.status}">
    <span th:case=400 th:text="${res['msg']}"></span>
    <img  th:case=200 th:src="${res['img']}" />
</div>

</body>
</html>